Add viewmodel-compose module that provides a utility function for Jetpack Compose.

gradle/libs.versions.toml

@@ -8,6 +8,8 @@ kotlin = "1.6.10"
 kotlinCoroutines = "1.6.0"
 kotlinMetadataJvm = "0.4.2"
 ksp = "1.6.10-1.0.4"
+compose = "1.1.1"
+androidxActivity = "1.4.0"
 androidxAppcompat = "1.4.1"
 androidxConstraintlayout = "2.1.3"
 androidxFragment = "1.4.1"
@@ -54,6 +56,16 @@ kotlin-metadata-jvm = { group = "org.jetbrains.kotlinx", name = "kotlinx-metadat
 # ksp
 ksp-api = { group = "com.google.devtools.ksp", name = "symbol-processing-api", version.ref = "ksp" }
 
+# compose
+compose-material = { group = "androidx.compose.material", name = "material", version.ref = "compose" }
+compose-ui = { group = "androidx.compose.ui", name = "ui", version.ref = "compose" }
+compose-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4", version.ref = "compose" }
+compose-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling", version.ref = "compose" }
+compose-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview", version.ref = "compose" }
+
+# androidxActivity
+androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "androidxActivity" }
+
 # androidxAppcompat
 androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "androidxAppcompat" }
 
@@ -70,11 +82,13 @@ androidx-lifecycle-livedata-ktx = { group = "androidx.lifecycle", name = "lifecy
 androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "androidxLifecycle" }
 androidx-lifecycle-viewmodel-ktx = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-ktx", version.ref = "androidxLifecycle" }
 androidx-lifecycle-viewmodel-savedstate = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-savedstate", version.ref = "androidxLifecycle" }
+androidx-lifecycle-viewmodel-compose = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-compose", version.ref = "androidxLifecycle" }
 
 # androidxNavigation
 androidx-navigation-fragment = { group = "androidx.navigation", name = "navigation-fragment", version.ref = "androidxNavigation" }
 androidx-navigation-fragment-ktx = { group = "androidx.navigation", name = "navigation-fragment-ktx", version.ref = "androidxNavigation" }
 androidx-navigation-ui-ktx = { group = "androidx.navigation", name = "navigation-ui-ktx", version.ref = "androidxNavigation" }
+androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "androidxNavigation" }
 
 # androidxRoom
 androidx-room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "androidxRoom" }

settings.gradle

@@ -23,6 +23,7 @@ include ':savedstate'
 include ':savedstate-compiler'
 include ':viewmodel'
 include ':viewmodel-test'
+include ':viewmodel-compose'
 include ':viewmodel-test-mockitokotlin'
 include ':viewmodel-test-mockk'
 include ':lifecycle'

viewmodel-compose/.gitignore

@@ -0,0 +1 @@
+/build

viewmodel-compose/build.gradle

@@ -0,0 +1,42 @@
+plugins {
+    id 'com.android.library'
+    id 'org.jetbrains.kotlin.android'
+    id 'lich-library-android'
+}
+
+lichLibrary {
+    version = VERSION_NAME_VIEWMODEL
+    name = 'Lich ViewModel (for Jetpack Compose)'
+    description = 'Lightweight framework for managing ViewModels.'
+    url = 'https://github.com/line/lich/tree/master/viewmodel'
+}
+
+android {
+    compileSdk libs.versions.compileSdk.get().toInteger()
+
+    defaultConfig {
+        minSdk 21
+        targetSdk libs.versions.targetSdk.get().toInteger()
+        testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
+    }
+
+    buildFeatures {
+        compose true
+    }
+
+    composeOptions {
+        kotlinCompilerExtensionVersion libs.versions.compose.get()
+    }
+}
+
+dependencies {
+    api project(':viewmodel')
+    implementation libs.compose.ui
+    implementation libs.androidx.lifecycle.viewmodel.compose
+
+    androidTestImplementation project(':savedstate')
+    androidTestImplementation libs.bundles.test.instrumentation
+    androidTestImplementation libs.compose.material
+    androidTestImplementation libs.compose.ui.test.junit4
+    androidTestImplementation libs.androidx.navigation.compose
+}

viewmodel-compose/src/androidTest/AndroidManifest.xml

@@ -0,0 +1,8 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.linecorp.lich.viewmodel.compose">
+
+    <application>
+        <activity android:name=".LichViewModelTest$TestActivity" />
+    </application>
+
+</manifest>

viewmodel-compose/src/androidTest/java/com/linecorp/lich/viewmodel/compose/LichViewModelTest.kt

@@ -0,0 +1,204 @@
+/*
+ * Copyright 2022 LINE Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.linecorp.lich.viewmodel.compose
+
+import android.content.Context
+import androidx.activity.ComponentActivity
+import androidx.compose.material.Button
+import androidx.compose.material.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.test.junit4.createAndroidComposeRule
+import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.performClick
+import androidx.lifecycle.SavedStateHandle
+import androidx.navigation.compose.NavHost
+import androidx.navigation.compose.composable
+import androidx.navigation.compose.navigation
+import androidx.navigation.compose.rememberNavController
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.linecorp.lich.savedstate.initial
+import com.linecorp.lich.viewmodel.AbstractViewModel
+import com.linecorp.lich.viewmodel.ViewModelFactory
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertNotNull
+import kotlin.test.assertNotSame
+import kotlin.test.assertNull
+import kotlin.test.assertSame
+import kotlin.test.assertTrue
+
+@RunWith(AndroidJUnit4::class)
+class LichViewModelTest {
+
+    @get:Rule
+    val composeTestRule = createAndroidComposeRule<TestActivity>()
+
+    @Test
+    fun differentViewModelStoreOwner() {
+        var firstViewModel: SimpleViewModel? = null
+        var secondViewModel: SimpleViewModel? = null
+        composeTestRule.setContent {
+            val navController = rememberNavController()
+            NavHost(navController, startDestination = "One") {
+                composable("One") {
+                    // firstViewModel is owned by the current NavBackStackEntry.
+                    firstViewModel = lichViewModel(SimpleViewModel)
+                }
+            }
+            // secondViewModel is owned by TestActivity.
+            secondViewModel = lichViewModel(SimpleViewModel)
+        }
+        composeTestRule.waitForIdle()
+
+        assertNotNull(firstViewModel) {
+            assertEquals("", it.param)
+            assertFalse(it.isCleared)
+        }
+        assertNotNull(secondViewModel) {
+            assertEquals("", it.param)
+            assertFalse(it.isCleared)
+        }
+        assertNotSame(firstViewModel, secondViewModel)
+    }
+
+    @Test
+    fun navigateWithParamThenPopBackStack() {
+        var firstViewModel: SimpleViewModel? = null
+        var secondViewModel: SimpleViewModel? = null
+        composeTestRule.setContent {
+            val navController = rememberNavController()
+            NavHost(navController, startDestination = "One") {
+                composable("One") {
+                    firstViewModel = lichViewModel(SimpleViewModel)
+                    NavigateButton("Two") { navController.navigate("Two/foo") }
+                }
+                composable("Two/{param}") {
+                    secondViewModel = lichViewModel(SimpleViewModel)
+                    NavigateButton("One") { navController.popBackStack() }
+                }
+            }
+        }
+        composeTestRule.waitForIdle()
+
+        assertNotNull(firstViewModel) {
+            assertEquals("", it.param)
+            assertFalse(it.isCleared)
+        }
+        assertNull(secondViewModel)
+
+        composeTestRule.onNodeWithText("Navigate to Two").performClick()
+        composeTestRule.waitForIdle()
+
+        assertNotNull(firstViewModel) {
+            assertFalse(it.isCleared)
+        }
+        assertNotNull(secondViewModel) {
+            assertEquals("foo", it.param)
+            assertFalse(it.isCleared)
+        }
+        assertNotSame(firstViewModel, secondViewModel)
+
+        composeTestRule.onNodeWithText("Navigate to One").performClick()
+        composeTestRule.waitForIdle()
+
+        assertNotNull(firstViewModel) {
+            assertFalse(it.isCleared)
+        }
+        assertNotNull(secondViewModel) {
+            assertTrue(it.isCleared)
+        }
+    }
+
+    @Test
+    fun sameParentViewModelAcrossRoutes() {
+        var firstViewModel: SimpleViewModel? = null
+        var secondViewModel: SimpleViewModel? = null
+        composeTestRule.setContent {
+            val navController = rememberNavController()
+            NavHost(navController, startDestination = "Main") {
+                navigation(startDestination = "One", route = "Main") {
+                    composable("One") {
+                        firstViewModel = lichViewModel(
+                            SimpleViewModel,
+                            navController.getBackStackEntry("Main")
+                        )
+                        NavigateButton("Two") { navController.navigate("Two/foo") }
+                    }
+                    composable("Two/{param}") {
+                        secondViewModel = lichViewModel(
+                            SimpleViewModel,
+                            navController.getBackStackEntry("Main")
+                        )
+                        NavigateButton("One") { navController.popBackStack() }
+                    }
+                }
+            }
+        }
+        composeTestRule.waitForIdle()
+
+        assertNotNull(firstViewModel) {
+            assertEquals("", it.param)
+            assertFalse(it.isCleared)
+        }
+        assertNull(secondViewModel)
+
+        composeTestRule.onNodeWithText("Navigate to Two").performClick()
+        composeTestRule.waitForIdle()
+
+        assertNotNull(firstViewModel)
+        assertNotNull(secondViewModel)
+        assertSame(firstViewModel, secondViewModel)
+
+        composeTestRule.onNodeWithText("Navigate to One").performClick()
+        composeTestRule.waitForIdle()
+
+        assertNotNull(firstViewModel) {
+            assertFalse(it.isCleared)
+        }
+        assertSame(firstViewModel, secondViewModel)
+    }
+
+    @Suppress("TestFunctionName")
+    @Composable
+    private fun NavigateButton(text: String, onClick: () -> Unit = {}) {
+        Button(onClick = onClick) {
+            Text(text = "Navigate to $text")
+        }
+    }
+
+    class TestActivity : ComponentActivity()
+
+    class SimpleViewModel(savedStateHandle: SavedStateHandle) : AbstractViewModel() {
+
+        val param: String by savedStateHandle.initial("")
+
+        var isCleared: Boolean = false
+
+        override fun onCleared() {
+            isCleared = true
+        }
+
+        companion object : ViewModelFactory<SimpleViewModel>() {
+            override fun createViewModel(
+                context: Context,
+                savedStateHandle: SavedStateHandle
+            ): SimpleViewModel = SimpleViewModel(savedStateHandle)
+        }
+    }
+}

viewmodel-compose/src/main/AndroidManifest.xml

@@ -0,0 +1,2 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.linecorp.lich.viewmodel.compose" />

viewmodel-compose/src/main/java/com/linecorp/lich/viewmodel/compose/LichViewModel.kt

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2022 LINE Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.linecorp.lich.viewmodel.compose
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalSavedStateRegistryOwner
+import androidx.lifecycle.HasDefaultViewModelProviderFactory
+import androidx.lifecycle.ViewModelStoreOwner
+import androidx.lifecycle.viewmodel.compose.LocalViewModelStoreOwner
+import androidx.savedstate.SavedStateRegistryOwner
+import com.linecorp.lich.viewmodel.AbstractViewModel
+import com.linecorp.lich.viewmodel.ViewModelFactory
+import com.linecorp.lich.viewmodel.internal.LichViewModels
+
+/**
+ * Returns an existing ViewModel or creates a new one, associated with the given
+ * [viewModelStoreOwner].
+ *
+ * By default, the owner is provided by [LocalViewModelStoreOwner]. It is a Navigation back stack if
+ * the current composable is in a [NavHost](https://developer.android.com/jetpack/compose/navigation).
+ * Otherwise, the owner is usually a Fragment or an Activity.
+ *
+ * The created ViewModel is associated with the given [viewModelStoreOwner] and will be retained
+ * as long as the owner is alive (e.g. if it is an Activity, until it is finished or process is
+ * killed).
+ *
+ * This is a sample code:
+ * ```
+ * @Composable
+ * fun FooScreen(fooViewModel: FooViewModel = lichViewModel(FooViewModel)) {
+ *     // Use fooViewModel here.
+ * }
+ * ```
+ *
+ * @param factory A [ViewModelFactory] to create the ViewModel.
+ * @param viewModelStoreOwner The owner of the ViewModel that controls the scope and lifetime of
+ * the returned ViewModel. Defaults to using [LocalViewModelStoreOwner].
+ */
+@Composable
+fun <T : AbstractViewModel> lichViewModel(
+    factory: ViewModelFactory<T>,
+    viewModelStoreOwner: ViewModelStoreOwner = checkNotNull(LocalViewModelStoreOwner.current) {
+        "No ViewModelStoreOwner was provided via LocalViewModelStoreOwner"
+    }
+): T {
+    val context = LocalContext.current
+    return if (viewModelStoreOwner is HasDefaultViewModelProviderFactory) {
+        LichViewModels.getViewModelWithDefaultArguments(
+            context,
+            viewModelStoreOwner,
+            viewModelStoreOwner,
+            factory
+        )
+    } else {
+        val savedStateRegistryOwner = viewModelStoreOwner as? SavedStateRegistryOwner
+            ?: LocalSavedStateRegistryOwner.current
+        LichViewModels.getViewModelWithExplicitArguments(
+            context,
+            viewModelStoreOwner,
+            savedStateRegistryOwner,
+            factory,
+            null
+        )
+    }
+}